Mill

ABSTRACT

This invention provides a non-ball mill, which makes the material to circulate at high speed within the mill so as to crush the material by means of the impact and friction among the material themselves. The mill includes base, motor, body for forming milling chamber, return funnel, and outlet port. A shaft driven by a motor penetrates the milling chamber and is provided with a rotating assembly for rotating the material within the milling chamber. The milling chamber consists of an upper chamber and a lower chamber formed respectively by pyramidal upper and lower body, so as to make the material to circulate within the milling chamber. A separating chamber is provided at the upper portion of the upper chamber, and the separator mounted on the shaft output the material of fine size to the outlet port. The mill has the advantageous of less energy consumption, no consumption of steel, light weight, high productivity, reduced wearing rate, small noise and vibration. The mill may be operated in either wet milling or dry milling manner, and combine crushing and separating operation together within a single device.

BACKGROUND OF THE INVENTION

This invention relates to a non-ball crushing mill, and particularly toa mill in which the material are crushed by the collision and frictionbetween the material during the high speed circulating movement withinthe mill, without the necessitate of making use of steel balls. Thiskind of mill has a wide application in various technical fields such asmineral separation, metallurgy, chemistry, building material industry,ceramic industry, and power plant.

DESCRIPTION OF THE PRIOR ART

The existing ball mill makes use of steel balls to crush the materiallike mineral. A large amount of steel balls will be consumed during thisoperation. In addition, the hardness of steel balls can only be thelevel of 7-8, while the hardness of some kind of mineral reaches thelevel of 8-9, even 10. Therefore, it is either difficult to crush thematerial or to reach high efficiency by means of the conventional ballmill. On the other hand, the weight of rotating parts and steel ballstakes about 95% by weight of the total weight of the rotating portion ofa conventional ball mill. This proportion is much higher than that ofmaterial to be crushed, therefore the energy consumption needed forobtaining crushed material of unit weight is rather high. The steelballs used in this kind of mill will be worn out during the crushingoperation, which will reduce the purity of some kind of products orcause environment contamination. In addition, the ball mill can not beused as a floatation unit simultaneously.

BRIEF DESCRIPTION OF THE INVENTION

One object of this invention is to provide a non-ball mill which makesthe material to circulate at high speed within the mill so as to crushthe material by the collision and friction produced between the materialas such. This kind of mill has a very few steel consumption and low rateof parts wear-out. The overall weight, particularly the weight ofrotating parts of the device, is reduced considerably, therefore theenergy consumption can be reduced and the efficiency improvedremarkably.

Another object of this invention is to provide a mill with low noise,low vibration and no environment contamination.

A still another object of this invention is to provide a mill capable ofperforming the separating and crushing operation simultaneously.

The mill for realizing the above mentioned objects includes base, motor,milling chamber, inlet funnel, outlet port, and wherein;

said milling chamber is divided by a return funnel into an upper chamberand a lower chamber, a central channel being formed at the centralportion of the return funnel and a return channel being formed betweenouter peripheral edge of the return funnel and the inner surface of themilling chamber, so as to circulate the material back and forth to theupper and lower chamber with high speed, causing the material to becrushed by collision and friction produced during high speed movement;

a rotating assembly driven by the motor through a shaft inserted intothe milling chamber being provided in said lower chamber, so as to makethe material to rotate at high speed;

a separating chamber being provided at central portion of the upperchamber, and a separating rotor being provided within said separatingchamber and fixed on the shaft;

said outlet port being communicated with an output opening located atthe top of said separating chamber.

In order to make the material to circulate more effectively at highspeed through the upper and lower chamber, the body forming the millingchamber is divided into an upper body and a lower body, the upperchamber and lower chamber being formed respectively within the upper andlower body, a top cover being provided at the top of the upper body.Both of the upper and lower body have the shape of pyramid with the baseends of the two pyramids jointed together, so that the whole millingchamber looks like a Rugby with a larger middle portion and two smallend portions.

Both the upper and lower body preferably have the shape of hex-pyramid.In other words, the horizontal section view perpendicular to the axis ofthe pyramid is a regular hexagon.

Each vertex angle of the pyramid forming the upper and lower body ispreferably 120°.

In addition, a plurality of barricades are protruded vertically fromeach edge of the pyramidal upper and lower body, so that the materialmoving at high speed may accumulate, after crushed, on the corner formedby intersection of the barricades and the body to form a layer ofmaterial capable of protecting the body and barricades.

The rotating assembly includes a hub connected with the shaft, a baseplate fixed on the outer peripheral surface of the hub, a plurality ofrotor blades fixed at equal distance on the upper surface of the baseplate, a plurality of bottom blades fixed at equal distance on thebottom surface of the base plate, and a protecting ring for connectingand strengthening the blades. A plurality of small holes are formed atthe central portion of the base plate so as to allow the crushedmaterial to pass through.

Alternatively, the above mentioned blades and strengthening rings may bereplaced by a plurality of accelerating bars pivotally mounted at thecentral portion of the base plate. A concave surface coated with wolfram(tungsten) or wolfram alloy are formed on the side of the acceleratingbars towards the rotation direction so as to prolong considerably theservice life of the rotating assembly.

The motor is connected with the shaft by a ball bearing of the type usedfor universal coupling, so that the driving torque of the motor can betransmitted properly even when vibration or deviation occurs during theoperation.

The bearing for supporting the shaft are suspended to the frame by meansof a number of anti-vibration means with tension springs, which willreduce the vibration produced during the operation, particularly duringstarting and stop procedures.

The base may be made in form of triangle. A height adjustable supportingfoot is provided at each corner of the base. The supporting footconsists of a ground foot of large surface and a screw-nut unit. Thebase has a good stability because it has a structure of three groundcontacting points. Since the ground foot has a large supporting surface,the mill according to this invention may be installed directly on groundwith various machnical property. The screw-nut unit is used foradjusting the verticality of the shaft.

In order to facilitate the install and maintenance, the mill is furtherprovided a lifting device consisting of a height adjustable liftingframe, an electrical lifter mounted on the horizontal beam of thelifting frame, and steel ropes.

The outlet port of the inlet funnel is preferably located exactly abovethe central channel of the return funnel.

In order to maintain the temperature within the milling chamber to about300° C. when the mill operates in dry milling manner, a heat absorbingwater tank filled with circulating water is provided outside the lowerbody, which is able to absorb heat produced by the collision andfriction between the material and therefore keep the strength of thesteel plate (16Mn or 45Mn2) forming the body of the milling chamber to aoptical degree. In addition, in order to prevent the damage of thebearing caused by too much heat transmitted to the bearing supportingthe shaft, and another water tank filled with circulating water isprovided below the bearing for supporting the shaft.

When the mill is used for operating in dry milling manner, according tothe different requirement as to the granularity of the products, theseparating propeller within the separating chamber may be provided withblades of different diameter and different helical angle.

When the mill is used for operating in dry milling manner, its outletport may be connected with a extra-fine separating device. Theextra-fine separating device includes a inlet funnel located at theupper portion of the separating chamber, a motor mounted near the outletport, a housing which is connected with the outlet port and includesoutlet funnel and subdivided outlet pipe. A shaft connected with themotor and inserted into the housing has staged blades fixed on theshaft.

When the mill is used for operating in dry milling manner, an air returnport at the bottom of the milling chamber of the mill is connected withthe housing of the extra-fine separating device by an air return pipe,so as to avoid the contamination caused by flying of the dust.

When the mill is used for operating in dry milling manner, thegranularity of the product can be adjusted by a control valve mounted atthe outlet port.

When the mill is used for operating in wet milling manner, said inletfunnel may be used to inlet water in addition to material.

The mill for wet milling may include further a floating device. Thefloating device includes an air inlet pipe which is mounted over theshaft and inserted into the milling chamber and has a plurality of airinlet holes at its upper portion and a plurality of air outlet holes atits lower portion; a slag discharge port located at the bottom of themilling chamber, a slag discharge valve mounted within the slagdischarge port, and an oil tank for oil dropping into the inlet funnelused for floating separation.

DESCRIPTION OF DRAWINGS

FIG. 1 is a schematically partial sectional view showing one embodimentof the mill according to this invention when operated in wet millingmanner;

FIG. 2 is a schematic view showing the structure of the rotatingassembly used in the embodiment of the mill according to this invention;

the left and right side of FIG. 3 are respectively the top and bottomview of the rotating assembly as shown in FIG. 2;

FIG. 4 is a schematic sectional view showing the structure of the airinlet pipe for floating separation as shown in FIG. 1;

FIG. 5 is schematic sectional view showing the ball bearing of the typeused for universal coupling and spring suspension unit adopted in themill according to this invention;

FIG. 6 is a schematic sectional view showing one embodiment of the millaccording to this invention when operated in dry milling manner;

FIG. 7 is a schematic view showing another embodiment of the rotatingassembly of the mill according to this invention as well as the crushingoperation of the material;

FIG. 8 is the A--A sectional view of FIG. 7.

DESCRIPTION OF PREFFER EMBODIMENTS

The structure and operation of the mill according to the presentinvention will be described in detail with reference to the accompanyingdrawings.

Referring to FIG. 1, it shows an embodiment of the mill according tothis invention, which is operated in wet milling manner and is providedwith a floatation device. A milling chamber 3 consisting of upper body4, lower body 5 and top cover 7 is fixed on an triangle base 1. As shownin FIG. 1, the upper body 4 and lower body 5 are both of hex-pyramidwith the vertex angle of 120° and made by steel plate with the thicknessof 40-50 mm. The larger ends of the upper and lower body 4,5 are jointedtogether. In order to prolong the service life of the body, lining layermay be provided on the inner surface of the bodies. A return funnel 6 isprovided at the center of the milling chamber 3 to divide the millingchamber 3 into an upper chamber 4' and a lower chamber 5' formedrespectively within the upper body 4 and lower body 5. A plurality ofbarricades 17,17' are mounted respectively on each edge of thehex-pyramid within the upper body 4 and lower body 5, which will causethe material in the milling chamber 3 to accumulate on the intersectioncorner of the barricades and the body so as to form a layer of materialcapable of protecting the body and barricades.

A frame 32 is secured on the top cover 7 for mounting motor 31,suspension frame 40, anti-vibration spring 34, etc.. The motor 31 isconnected with a rotating shaft 30 through a ball bearing 33 of the typeused for universal coupling. The shaft 30 is supported by two bearings35, and the bearing seats of the bearings 35 are suspended within theframe 32 by means of a plurality of the anti-vibration springs throughsteel ropes (see FIG. 1 and FIG. 5).

The lower portion of the shaft 30 is inserted into the milling chamber3. A rotating assembly 19 and an air inlet pipe 26 for floatingseparation are fixed respectively on this portion along the down-to-updirection by means of nut 33.

A conical cylinder with its larger end located upward is provided at thecentral portion of the top cover 7, and a separating chamber is formedwithin the conical cylinder. In this separating chamber, a separatingrotor 29 is secured on the air inlet pipe 26, and the central hole ofthe top cover 7 is communicated with the outlet port 45 of the outletchannel provided on the top cover 7.

The rotating assembly 19 is located within in the lower chamber and hasthe structure as shown in FIGS. 2, 3. A hub 20 is fixed on the rotatingshaft 30 by means of a key, and a base plate 21 is welded on the hub 20.A plurality of small holes are formed on the central portion of the baseplate 21 so that the crushed powder of greater specific gravity may passdown to the bottom portion of the lower chamber. Six pieces of blade 22are provided uniformly on the top surface of the base plate 21, and areinforcing ring 24 is welded on the top of the blades 22. Another sixpieces of blade 23 are provided at equal angular distance on the bottomsurface of the base plate 21. The main function of the blade 22 is tomake the material entered into the central space of the rotatingassemble to rotate at high speed. Then, the material will be thrown outalong the tangential direction of the peripheral edge of the rotatingassembly 19 by the centrifugal force produced during high speedrotation. The material thrown out will collide and rub with the materialstaying previously adjacent to the wall of the body so as to cause thematerial crushed. The manner by which the material are crushed will beexplained more detail hereinafter in connection with the description forthe operation procedure of the mill of the present invention. Inaddition to the effect of reinforcing the base plate 21, the bottomblades 23 also play the role of a fan. The upper and inner corner ofeach blade 22 is cutaway and the lower and outer corner of each bottomblade 23 is also cutaway, so that a uniform space is formed respectivelybetween the blades and the declined surface of the funnel 6 and thelower body, which will avoid the interference produced between them. Thedeclining angle α1 and α2 of the cutaway corner should coincide with thedeclining angle of the lower body and the funnel. The speed of thematerial thrown out from the rotating assemble may be as high as 40-120m/sec.

FIG. 7 shows schematically the structure of another embodiment of therotating assembly 19'. In the rotating assemble 19' the blades 22 arereplaced by accelerating bars 22'. The accelerating bars 22' arepivotally mounted on the central portion of the base plate by means ofrotating pins 25 so that they may swing around the pins freely toproduce a buffering effect during impacting with the material. Thelateral sectional view of the accelerating bars 22' is shown in FIG. 8.It can seen from FIG. 8 that a concave surface B is formed at one sideof the bar toward the rotating direction of the rotating assembly. Alayer of wolfram (tungsten) powder or wolfram alloy is plated on theconcave surface B and then polished. It has been proved by experimentthat the rotating assembly of the above mentioned structure may reducethe wearing rate of the accelerating bars (or blades) to a minimumdegree.

Turn back to FIG. 1, three height-adjustable supporting feet 2 areprovided respectively one at each corner of the triangle base 1 foradjusting the horizontality of the base 1 or the verticality of therotating shaft 30 within the milling chamber. The adjusting unitincludes screw stem 2' and nut engaged with the screw stem. Since thesupporting feet 2, as shown in FIG. 1, has a large bottom surfacecontacting with the ground, it is possible to set the mill directly ondifferent kinds of ground without the necessity of constructing specialfoundation for it.

An inlet funnel 14 is inserted into the upper chamber with its outputport located adjacent to the central pass 15 of the return funnel 6, sothat the material to be processed can enter easily into the lowerchamber to obtain the required high rotating speed. An oil tank 8 isfilled with oil for floating separation. The oil can drop into thereturn funnel 14 through the pipe located at the lower part of the tankand then enter the milling chamber together with the material.

A horizontal beam 42 is protruded transversely from the top of thesuspension frame 40 and an electrical lifter 43 mounted on the beam 42can move freely along the horizontal beam 42. The vertical beam 41 ofthe suspension frame 40 has a telescopic structure, so that theoperation of assembling and disassembling heavy parts during theassembling and maintaining procedure can be carried out by the deviceitself. This feature makes the device suitable for field operation.

FIG. 4 shows an air inlet pipe 26 for floating separation which isdesigned for this embodiment. The upper portion of the pipe 26 isoutside the top cover 7 of the milling chamber and a plurality of airinlet holes 27 are formed on this portion. The lower portion of the pipe26 is inserted into the center of the milling chamber and a plurality ofair outlet holes 28 are formed on the peripheral surface of the thisportion. By means of the negative pressure produced at the centralportion of the lower chamber 5' during the rotation of the rotatingassembly, air may be sucked into the air inlet pipe 26 through the airinlet holes 27 and then released in the form of air bubbles from the airoutlet holes 28 to produce the air bubbles needed for carry out thefloating separation.

The operation of the mill according to this invention operated in wetmilling manner together with the floating separation device will now bedescribed in detail.

Material with granular size less than 100 mm, water, and oil forfloating separation enter into the central of the milling chamber 3through the inlet funnel 14. The motor 31 will, when turned on, drivethe shaft 30 and the rotating assembly to rotate at high speed, so thatthe water (optionally oil) and the material will also rotate at highspeed around the rotating axis by means of the blades 22 (or bars 22').Due to the centrifugal force produced during the rotation, water andmaterial will move radically toward the outer edge while rotating aroundthe axis. Moreover, the material move radically in a rolling manner.When the material arrive at the outer edge of the blades 22 (or bars22'), they will be thrown out along the tangential direction with aspeed as high as about 40 m/s. As shown by the arrow D in FIG. 7, duringthe period that the blades 22 (or bars 22') rotate across an angle of60°, the material flying out from this sector will either impactdirectly on the corner L formed by barricades 17 and lower body 5 or bereflected toward the corner L. Therefore, the crushed material willaccumulate at the corner L to form a protective layer. The materialflying out from the rotating assembly thereafter will impact on thematerial accumulated previously and be crushed by the collision andfriction produced between the material themselves.

Since the lower body has a pyramidal shape with its larger end locatedupward, the material impacting on the wall of the lower body 5 willobtain a velocity component of upward movement, so that the crushedmaterial will move toward the upper chamber through the gap between thereturn funnel and the body as shown in FIG. 1. Since the upper body 4has a pyramidal shape with its larger end downward, the materialimpacting on the wall of upper body 4 will have a tendency to movedownward and centripetally. In addition, a negative pressure will beproduced at the central portion by means of the outward movement of thewater and the material. For these reasons, the material will fall to thecentral portion of the milling chamber and return back to the lowerchamber 5' through the central pass 15 of the return funnel 6. Thematerial will move back and forth in such a manner to form a cyclingmovement. The overall movement path of the material during the millingoperation may be represented by the circle of dotted line and arrow C asshown in FIG. 1.

Since the speed of water is 5-10 times lower than that of material, thepower output of the motor is used mainly for driving the material tocollide with each other.

In addition, the rotor 29 mounted on the air inlet pipe 26 for floatingseparation rotates together with the shaft 30 too, it makes the airbulbs and water entered into the milling chamber through the air outletholes 28 to carry the crushed material of the predetermined size to flowupward through the hole at the central portion of the top cover 7 intothe outlet channel, and then to flow from the outlet port 45 into acollecting channel (not shown). The material of larger size will bethrown out by the rotor 29 and then fall down into the central portionof the milling chamber after impacting with the inner wall of thecentral cone 18 of the top cover 7 so as to rejoin the cycling of thematerial.

The fine powder will fall down through a plurality small holes on thecentral portion of the base plate 21 into the bottom of the lowerchamber, among which, the powder of relatively small specific gravitywill be thrown out again by the bottom blades and flow toward the upperpart of the lower chamber, and the slag powder of relatively largerspecific gravity will deposit gradually on the bottom. When a slagdischarge valve 13 is opened, the slag will be discharged through thevalve within a slag discharge port 12 into an underground channel.

The mill of the embodiment may also be used only for wet milling withoutfloating separation. For this purpose, it is only necessary to cancelthe air inlet holes and air outlet holes on the two ends of the pipe 26and to stop the oil dropped into the return funnel.

Referring to FIG. 6, which shows schematically the structure of the millaccording to this invention for dry milling, which is operated togetherwith a extra-fine separating device. The structure and effect of themill for dry milling is substantially the same as that of the mill forwet milling as mentioned above, except for only material and air putinto the milling chamber through the return funnel, without water andoil.

In addition, since the heat conducting effect of air is much poorer thanthat of water, in order to prevent the reduction of strength of variouspart of the device due to overheating caused by the heat produced duringthe milling procedure, a cooling water jacket 80 is added outside of thelower body for cooling the lower body by cycling water. In addition, inorder to prevent damage of the bearing caused by the heat conducted toit, a cooling water jacket 81 filled with cycling water is also providedat the location below the bearing (shown in FIG. 5).

The extra-fine separating device as shown in the left side of FIG. 6 hasthe following structure. The motor 53 installed at the top of the frameis connected with a shaft 52 through a coupling. The shaft 52 isinserted into a housing 51. A suction fan and several groups of stagedblades 54 are fixed respectively on the shaft 52. With respect to eachgroup of the blades 54, each one outlet port 50 is provided on the body51 to output the product powder of different size into different bagsconnected with respect outlet ports. An air return port 55 is designedon the upper part of the housing, one end of the port 55 is communicatedwith an air return pipe 56 and another end is communicated with an airreturn port 57 located at the bottom of the milling chamber.

In the separating chamber, the fine powdered material are pushed upwardby the propeller of the separator fixed on the shaft. When arriving atthe edge of upper port of the separating chamber, the powders ofrelatively larger size will, due to the reduction of the push force aswell as the effect of relatively larger weight, fall back to the millingchamber for further milling. The powder of relatively smaller size willpass through the outlet port and enter into the extra-fine separatingdevice.

The dimension and angle of the blades of the above mentioned separatingrotor may by selected according to different requirements respect to thesize of powder and specific gravity of the material so as to obtain theproduct with satisfactory granularity. In addition, the granularity ofthe separated product may also be adjusted by changing the openingdegree of the butterfly valve mounted at the outlet port.

After the material leaving from the outlet port enter into theextra-fine separating device along the tangential direction, the powderof largest size will at first be collected in the funnel 49 by means ofa cyclone process and then outputted from the lower port. Then, the airflow will move upward to separate the material of different size bymeans of different groups of staged blades. The separated material ofdifferent size will be outputted into respect bags. Finally, the airflow with very small amount of remained powders will return back to thelower part of the milling chamber through the air return port 55 and airreturn pipe 56.

The non-ball mill according to this invention has the followingadvantageous:

1. In comparison with the known ball mill, the consumption of steel canbe reduced to about zero and the productivity is rather high since thematerial are crushed by the high speed collision and friction producedamong themselves.

2. In comparison with the known ball mill, the steel material requiredfor making the device is reduced by 90%. The weight of the rotating parttakes only 10% of the overall weight of the device, so that theelectricity consumption may be reduced to 1/5, which in turn increaseconsiderably the economic efficiency.

3. Since the milling chamber is designed to have a pyramidal shape and abarricade is provided at each edge of the pyramid, the material arecirculated automatically within the milling chamber along a cycling pathand are accumulated at the intersection corners of the body andbarricades to form a protective layer, so that the wearing rate of thebody or its lining layer nay be reduced while the milling efficiencyincreased.

4. Since the adoption of the height adjustable triangle supporting feetfor adjusting the main shaft to an exact vertical position, the adoptionof the ball bearing of the type used for universal coupling forconnecting motor and shaft, as well as the adoption of elasticanti-vibration device, the mill has the features of low noise andvibration, which enable the device to be set directly on ground of anykind without the necessity of foundation construction.

5. Since a lifting device is provided, the device may by installed andmaintained conveniently.

6. The mill according to this invention may combine the crushing andseparating operation into one single device, it can be used either forwet milling with floating separation or for dry milling withmultiple-staged separation.

I claim:
 1. A mill comprising:a base; a body mounted on the base anddefining a milling chamber, the body having an inlet port and an outletport; a return funnel positioned in the milling chamber and dividing themilling chamber into an upper chamber and a lower chamber, the funnelhaving a central channel formed at central portion of the return funnel,the funnel defining a return channel between an outer peripheral edge ofthe return funnel and an inner surface of the milling chamber; a frameextending above the body and supported thereon; a motor mounted on theframe; a shaft connected to the motor and extending into the millingchamber; a rotating assembly rotatably provided in the lower chamber anddriven by the shaft connected to the motor, centrifugally forcingmaterials in the lower chamber to be driven against the inner surface ofthe milling chamber causing the material to be crushed by collision andfriction produced during high speed movement and causing the crushedmaterial to circulate through the return channel, the upper chamber, andthe central channel back to the lower chamber with high speed; aseparating chamber being provided at a central portion of the upperchamber; and a separation rotor provided within the separating chamberand fixed on and rotating with the shaft; the outlet port beingcommunicating with an output opening located at the top of theseparating chamber.
 2. A mill according to claim 1, wherein the bodyforming the milling chamber comprises an upper body and a lower body,each of the upper body and the lower body being a pyramid shape havingwith a larger end of each of the two pyramid shapes joined together toform the body, the upper chamber and lower chamber being formedrespectively within the upper body and lower body, and wherein a topcover is provided at the top of the upper body.
 3. A mill according toclaim 2, wherein each the pyramid shape is a hexagonal pyramid havingthe large end being a six sided base.
 4. A mill according to claim 3,wherein the vertex angle of each pyramid shape is 120°.
 5. A millaccording to claim 2, further comprising a plurality of vertical platebarricades are provided in the upper body and in the lower body, eachplate barricade in the lower body extending from the inner surface ofthe lower body to a position adjacent the rotating assembly.
 6. A millaccording to any one of claims 1-5, wherein the rotating assemblyincludes a hub connected with the shaft, a base plate fixed on an outerperipheral surface of the hub, a plurality of rotor blades fixed atequal distance apart on an upper surface of the base plate, a pluralityof bottom blades fixed at equal distance apart on a bottom surface ofthe base plate, and a protective ring connected to upper edges of therotor blades, wherein a plurality of small holes are formed in a centralportion of the base plate allowing crushed material to passtherethrough.
 7. A mill according to claim 6, wherein the shaft issupported on the frame by bearings, the bearings including bearing seatsand ball bearings in the bearing seats, and the bearing seats aresuspended to the frame by plural anti-vibration springs.
 8. A millaccording to claim 6, wherein the base is in the shape of a trianglehaving three corners, and the mill further comprises a height adjustablesupporting frame provided at each corner of the base, each the heightadjustable supporting frame including a ground foot and a screw-nut unitadjustably connecting the ground foot to the corner.
 9. A mill accordingto claim 6, wherein the mill further includes a lifting device formaintenance comprising of a height adjustable lifting frame, anelectrical lifter mounted on a horizontal beam of the lifting frame, andsteel rope attached to the motor and operatively associated with theelectric lifter.
 10. A mill according to claim 6, wherein the inlet portincludes an inlet funnel for providing water in addition to materialinto the body.
 11. A mill according to any one of claims 1-5, whereinthe rotating assembly includes a hub connected with the shaft, a baseplate fixed on an outer peripheral surface of the hub, a plurality ofbottom blades fixed at equal distance apart on a bottom surface of thebase plate, and a plurality of accelerating bars pivotally mounted at acentral portion of the base plate, wherein a plurality of small holesare formed in the central portion of the base plate allowing crushedmaterial to pass therethrough, and the side of the accelerating barseach have a side oriented in a direction toward a rotating direction ofthe rotating assembly, the side having a concave surface coated with alayer of tungsten or tungsten alloy.
 12. A mill according to claim 11,further comprising a heat absorbing water jacket provided outside andsurrounding the lower body; and a cooling water jacket adjacent abearing supporting the shaft.
 13. A mill according to claim 12, whereinthe separation rotor is provided with blades having a helical angle. 14.A mill according to claim 12, further comprising an extra-fineseparating device connected to the outlet port, the extra-fineseparating device including a separating device inlet funnel located atan upper portion of the separating chamber, a motor mounted near theoutlet port, a separating body connected with the outlet port andincluding an outlet funnel and a subdivided outlet pipe, a shaftconnected with the motor and inserted into the separating body, andplural stepped blades fixed on the shaft.
 15. A mill according to claim14, wherein a bottom of the milling chamber has an air return port andan air return pipe connects the separating body to the air return port.16. A mill according to claim 12, further comprising an output controlvalve on the outlet port for adjusting the granularity of outputtedmaterial.
 17. A mill according to claim 11, wherein the shaft issupported on the frame by bearings, the bearings including bearing seatsand ball bearings in the bearing seats, and the bearing seats aresuspended to the frame by plural anti-vibration springs.
 18. A millaccording to claim 11, wherein the base is in the shape of a trianglehaving three corners, and the mill further comprises a height adjustablesupporting frame provided at each corner of the base, each the heightadjustable supporting frame including a ground foot and a screw-nut unitadjustably connecting the ground foot to the corner.
 19. A millaccording to claim 11, wherein the mill further includes a liftingdevice for maintenance comprising a height adjustable lifting frame, anelectrical lifter mounted on a horizontal beam of the lifting frame, andsteel rope attached to the motor and operatively associated with theelectric lifter.
 20. A mill according to claim 11, wherein the inletport includes an inlet funnel for providing water in addition tomaterial into the body.
 21. A mill according to any one of claims 1, 2and 5, wherein the shaft is supported on the frame by bearings, thebearings including bearing seats and ball bearings in the bearing seats,and the bearing seats are suspended to the frame by pluralanti-vibration springs.
 22. A mill according to any one of claims 1, 2and 5, wherein the base is in the shape of a triangle having threecorners, and the mill further comprises a height adjustable supportingframe provided at each corner of the base, each the height adjustablesupporting frame including a ground foot and a screw-nut unit adjustablyconnecting the ground foot to the corner.
 23. A mill according to anyone of claims 1, 2 and 5, wherein the mill further includes a liftingdevice for maintenance comprising a height adjustable lifting frame, anelectrical lifter mounted on a horizontal beam of the lifting frame, andsteel rope attached to the motor and operatively associated with theelectric lifter.
 24. A mill according to any one of claims 1, 2 and 5,wherein the inlet port includes an inlet funnel for providing water inaddition to material into the body.
 25. A mill according to claim 24,wherein an output port of the inlet funnel is positioned above thecentral channel of the return funnel.
 26. A mill according to claim 24,further comprising a floating device, the floating device including anair inlet pipe located outside the shaft and inserted into the millingchamber, the air inlet pipe having a plurality of air inlet holes at anupper portion and a plurality of air outlet holes at a lower portion, aslag discharge port located at the bottom of the milling chamber, a slagdischarge valve mounted within the slag discharge port, and an oil tankfor dropping oil into the return funnel for floating separation of thecrushed material.